External cavity quantum cascade lasers (QCLs) may be used in high resolution molecular spectroscopy and molecular sensing applications. Stable optical feedback into the active gain region of the QCL semiconductor crystal is very sensitive to the precise alignment of the external cavity optics since this active gain region has dimensions comparable to the wavelength of the laser radiation, i.e. a few micrometers. The external cavity is subject to alignment noise and drift, which may degrade signal-to-noise ratio and sensitivity of the system for its intended application.